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The current study is dedicated to presenting the Casson nanofluid over a stretching surface with activation energy. In order to make the problem more realistic, we employed magnetic field and slip effects on fluid flow. The governing partial differential equations (PDEs) were converted to ordinary differential equations (ODEs) by similarity variables and then solved numerically. The MATLAB built-in command 'bvp4c' is utilized to solve the system of ODEs. Central composite factorial design based response surface methodology (RSM) is also employed for optimization. For this, quadratic regression is used for data analysis. The results are concluded by means of tables and pictorial representations. The present study discloses that the temperature profile increases with enhancement in Ha , Nr, Nb, and Ntand it shows opposite behavior for λ. The included parameters show same trend for heat transfer rate (Nu x ). It is also concluded that δ should be maximum for any value of Nband Ntto maximize the heat transfer rate. [ABSTRACT FROM AUTHOR]

Nonsimilar equations exist in many fluid flow problems and these equations are difficult to be solved using variation of the physical parameters. The key purpose of this study is to find nonsimilarity solution of nanofluid on an exponentially shrunk sheet in the existence of micropolar nanofluid without considerations of the thermal radiation and viscous dissipation effects. The governing partial differential equations (PDEs) are transformed into nonsimilar equations consisting of both ordinary and PDEs. Numerical results of velocity, microrotation, heat and concentration are presented in graphs. The results reveal that fluid particles' velocity decreases nearby surface and increases afterward. The skin friction, heat and concentration transfer rate are also plotted to perceive the phenomena with different physical situations. It can be deduced that wall shear force f ′ ′ (0) is improved by developed effects of micropolar fluid parameter K and reduced by increasing values of Hartmann number M. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this paper is to study the thermal behavior of radial porous fin surrounded by water-base copper nanoparticles under the influence of radiation. Design/methodology/approach: In order to optimize the response variable, the authors perform sensitivity analysis with the aid of response surface methodology (RSM). Moreover, this study enlightens the applications of artificial neural networks (ANN) for predicting the temperature gradient. The governing modeled equations are firstly non-dimensionalized and then solved with the aid of Runge–Kutta fourth order together with the shooting method in order to guess the initial conditions. Findings: Numerical results are analyzed and presented in the form of tables and graphs. This study reveals that the temperature of the fin is decreasing as the wet porous parameter increases (m2) and the temperature for 10% concentration of nanoparticles are higher than 5 and 1%. Physical parameters involved in the study are analyzed and processed through RSM. It is come to know that sensitivity of temperature gradient to radiative parameter (Nr) and convective parameter (Nc) is positive and negative to dimensionless ambient temperature (θa). Furthermore, after ANN training it can be argued that the established model can efficiently be used to predict the temperature gradient over a radial porous fin for the copper-water nanofluid flow. Originality/value: To the best of our knowledge, only a few attempts have been made to analyze the thermal behavior of radial porous fin surrounded by copper-based nanofluid under the influence of radiation and convection. [ABSTRACT FROM AUTHOR]